There is a desire to reduce the amount of paper flow in many of today's business and non-business environments. For example, it would be desirable to provide some type of electronic postage delivery system to enhance electronic mail or electronically communicated information among different parties in a session or transaction. Information systems are increasingly employing data encryption algorithms, cryptographic engines, and devices to facilitate secure communication of data from one point to another. In addition, digital signature techniques are also being used to apply a digital signature to encrypted or unencrypted data so that the recipient can determine the source of the data accompanying digital signature. As known, both asymmetric and symmetric cryptography systems may be employed to facilitate the encryption, and decryption in digital signing of information.
Many postal systems use a form of recorded document delivery indicating that a particular piece of paper mail was forwarded to a particular address. This may typically include, for example, a postal employee delivering by hand the mail and having a person that receives the particular piece of mail, sign a receipt. This person may or may not be the intended recipient. In addition, the postal employee may also sign a receipt indicating that it was delivered to a particular address. Also, many other document delivery processes are in place to provide proof of delivery of a particular piece of mail. For example, the actual signature of the recipient may be required before the piece of postal mail is left with the recipient. However, typical postal delivery systems require the use of postal employees throughout the various steps in the process and can take many hours and even days. Consequently, a desire exists to reduce the cost of such systems while attempting to increase the speed of delivery of information. The information must also be delivered in a secure manner to avoid detection by unscrupulous parties and should be secure from point to point so a third party does not have access to the information.
Privacy enhanced electronic data is well-known. For example, encrypted e-mails may be sent over the internet or other suitable network to another party. Public key and private key cryptographic systems also are well-known and typically employ a public encryption key and private decryption key and, if desired, a private signing key and public verification key. Today when electronic data is sent in encrypted form, for example to a recipient, there may be some indications as to whether or not the recipient received the message, however, the recipient can disconnect the link before reading a message and interrupt a verification message back to the sender indicating that the message had been received. If the data included a bill, the recipient could potentially claim that they never received the information.
Also as known, security tokens are typically sent as encrypted messages which may include, for example, security related information to provide the necessary encryption and decryption of information. For example, a security token may include data representing the algorithm that was used to perform the encryption and digital signature. The security token may also include the digital signature of the sender as well as an encrypted symmetric key. Generally, the symmetric key is used to encrypt the information and the public key of the recipient is used to encrypt the symmetric key. As such, the encryption process may include, for example, using a symmetric encryption process like DES. A symmetric key is encrypted using the recipients public asymmetric encryption key. The recipient uses its private decryption key to decrypt the encrypted symmetric key and uses the symmetric key to decrypt the contents so only the recipient can decrypt the information. Systems typically do not also encrypt the security token.
One technique used to help insure that the delivery of information has taken place may include, for example, the use of a digital notary system. In such a system, a sender sends data to a trusted third party. The trusted third party digitally signs the data and appends a time to the data. The signed data may then be sent back to the originator or forwarded to a recipient. The recipient then performs standard digital signature verification on the notary signature and then obtains the encrypted content and performs the decryption. However, such systems do not typically require that the notary provide a recipient with a decryption key or other data unlocking mechanism. Also desired, the sender may digitally sign the encrypted information and the notary first performs standard verification of originator's signature to ensure that the sender is a trusted party to the system. However, since typical digital notaries may store the encrypted message, they still provide some type of security risk even though they may be considered a trusted authority.
Consequently, there exists a need for a method apparatus for securely communicating data. It would be desirable if such a system and method employed some type of third-party enabling of secure data delivery so that proof of document submission and/or proof of delivery of a document, or other data, may be accommodated.